Why do i keep on holding on to our relationship even though i know he’s a wrong guy?

The most important thing is that you have understood that the relationship you are in is not right for you, so well done for that. If breaking up with him has not worked out when you're doing it alone why don't you ask a friend to help you out so that you are able to do it together and you won't feel guilted into apologising?? It may sound childish doing that but it won't take as long as the relationship could last. I can't tell you the reason you are still holding on though it could be low self esteem or you hoping he will get better, which you must assume he won't. There will come a time in life where you find somebody you feel completely comfortable with who you don't think can get any better :)

I think you should break up with him, because he sounds exactly like the type of guy who'll ruin your life. If you're scared you won't find someone else, you're wrong, because you're beautiful and totally worth loving! Try to be strong and find the courage to quit him because you DO deserve so much better.

There's something in economics called the sunken cost theory and it happens with relationships, too. You have this "thing" that you've put so much time and energy into that even though you want to get rid of it, you don't want all your efforts to go to waste. But you're going to have to let it go because that's what is going to be best for you. When you decide to break up, maybe it might be best to break contact with him for awhile. I wish you the best of luck. Break ups are not easy.